1. Field of the Invention
The present invention relates to membranes of the type employed for the temporarily covering a recess in the endogenic bone tissue filled with an osteogenic material, such as hydroxyapatite granules.
2. Description of the Prior Art
Following bone surgery, for example, in the reconstruction of bones in plastic surgery or in the case of operations on the jaw, it is standard practice to fill the bone defect or deficiency points, which are in the form of recesses or cavities in the endogenic bone tissue, with an osteogenic material. Such osteogenic material generally consists of a mixture of bone replacement material, such as hydroxyapatite granules and endogenic bone particles. To ensure that the osteogenic material grows substantially exclusively in an osseous manner from the bone side, but does not grow into surrounding mucous tissue, the recess is closed with a covering membrane of the type generally described above. The purpose of such a membrane is to ensure that there is no growth of the osteogenic material into the non-bone tissue. Only by ensuring complete osseous growth of the osteogenic material is it possible to substantially completely eliminate the bone defect point, and to reintegrate the osteogenic material into the endogenic bone after osseous growth has taken place.
Heretofore, polytetrafluoroethylene films have been used as such covering membranes, however, such known membranes have the disadvantage of remaining in the body when the bone defect point heals, and can therefore create complications.
As a result of the material used for conventional covering membranes, such as, for example, plastic films, the membrane is not stiff and can therefore change its position as a result of radial stressing transmitted through the surrounding soft body tissue as a result, for example, of muscular movements. Such movements of the covering membrane have the disadvantage that the transfer of the blood clot in the bone defect point into the bone tissue is impaired, because the portion of the osteogenic material which is near the membrane, or the portion of the blood clot which is near the membrane, is disturbed by the covering membrane movement.